On using eco-physiological, micrometeorological and biogeochemical theory to evaluate carbon dioxide, water vapor and trace gas fluxes over vegetation: a perspective

• Published in: Agricultural and forest meteorology 1998-03, Vol.90 (1), p.1-25
• Main Authors: Baldocchi, Dennis, Meyers, Tilden
• Format: Article
• Language: English
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; ATMOSFERA; ATMOSPHERE; Biogeochemistry; Biological and medical sciences; Biosphere–atmosphere interactions; CARBON DIOXIDE; DIOXIDO DE CARBONO; DIOXYDE DE CARBONE; ECHANGE GAZEUX; Eddy covariance measurements; EVAPORACION; EVAPORATION; Fundamental and applied biological sciences. Psychology; GAS EXCHANGE; GASES; GAZ; General agronomy. Plant production; Generalities, techniques; Generalities. Techniques. Climatology. Meteorology. Climatic models of plant production; INTERCAMBIO DE GASES; MODELE; MODELOS; Synecology; Terrestrial ecosystems; Trace gas fluxes; VAPEUR D'EAU; VAPOR DE AGUA; VEGETACION; VEGETATION; WATER VAPOUR
• ISSN: 0168-1923; 1873-2240
• DOI: 10.1016/S0168-1923(97)00072-5

How eco-physiological, biogeochemical and micrometeorological theory can be used to compute biosphere–atmosphere, trace gas exchange rates is discussed within the framework of a process model. The accuracy of the theory is tested by comparing computations of mass and energy flux densities (water vapor, sensible heat, CO 2 and ozone) against eddy covariance measurements over five distinct canopies (wheat, potato and soybean crops and a temperate broad-leaved and a boreal conifer forest). Once tested, the theory is used to evaluate how interactions between climate and vegetation might influence leaf area and photosynthetic capacity and, in turn, alter energy balance partitioning and the transfer rates of CO 2 and other trace gases over vegetation canopies. Model parameters, derived from biogeochemical and eco-physiological principles, enabled the model to estimate rates of mass and energy exchange with reasonable fidelity. In particular, the theory reproduced the magnitudes and distinct diurnal patterns associated with mass and energy fluxes over a spectrum of vegetation types. Model sensitivity tests revealed that variations in leaf area index and photosynthetic capacity interacted to increase rates of evaporation and carbon dioxide and pollutant uptake, greatly, and in a curvilinear manner. Finally, we conclude that the assignment of many model parameters according to plant functional type has much potential for use in global and regional scale ecosystem, climate and biogeochemistry models.